Zone 6BCold (Zone 6)
Climate Zone 6B - Cold, Dry
Short warm summers and long cold winters with low humidity. This climate zone encompasses parts of Montana, Wyoming, Idaho, Colorado and includes major cities like Helena, Casper, Bozeman, Jackson.
Design Temperatures
Winter Design Temperatures
-15°F to 5°F
Used for heating load calculations and equipment sizing
Summer Design Temperatures
75°F to 85°F
Used for cooling load calculations and equipment sizing
Heating & Cooling Degree Days
Heating Degree Days (HDD)
6,500 - 9,000
Base 65°F. Higher numbers indicate more heating requirements and longer heating seasons.
Cooling Degree Days (CDD)
0 - 500
Base 65°F. Higher numbers indicate more cooling requirements and longer cooling seasons.
HVAC System Considerations
Key Considerations
- •Extreme heating loads
- •Minimal cooling needs
- •High altitude effects
- •Equipment derating required
- •Freeze protection critical
Common Equipment
- ✓High-efficiency gas furnaces
- ✓Boilers
- ✓Radiant heating
- ✓Wood/pellet supplemental heat
Energy Code Requirements
Equipment Efficiency
- ⚠AFUE 90+ for furnaces
- ⚠High-performance windows
- ⚠Continuous insulation
- ⚠Air sealing requirements
Insulation Requirements
Walls:R-20 to R-21
Ceiling:R-49 to R-60
Floor:R-25 to R-30
Quick Reference
Zone:6B
Temperature:Cold
Moisture:Dry (B)
States:4
Cities:4
Calculate Load
Use our load calculators with the design temperatures and requirements specific to Zone 6B.